1. Field of the Invention
The invention relates to an electrical connector; more particularly, to a stacked electrical connector.
2. Description of the Prior Art
Recently, as the computer moves towards a thin and compact product, the size of motherboard in the computer is reduced, resulting in a limited space on the motherboard for the electrical components. Therefore, similar or different types of connectors or connection ports are assembled on the motherboard in a stacked way in order to optimize the space utilization. For example, multiple universal serial bus (referred to as USB hereinafter) (connection) ports may be arranged collectively on an insulator; alternatively, a number of different types of connection ports, such as USB ports, RJ45 ports, IEEE 1394 ports and high definition multimedia interface (referred to as HDMI hereinafter) ports, may be grouped together on a single insulator to form a stacked connector with multiports.
However, due to the property of high transmission rate of the connection port, high frequency electromagnetic wave (known as “electromagnetic (EM) radiation”) is emitted during the signal transmission process, by which the digital signal transmitted through the connector and further the operation of other electrical components in the computer will be affected adversely (known as “electromagnetic interference”, EMI). As a common solution, a conductive metal shell is formed to cover the insulator on which the connector is located and to secure to the motherboard at the same time. In this way, effective EM shielding can be provided because of the contact between the metal shell and the motherboard.
A stacked connector has been developed in which an open accommodating space is additionally formed in the insulator where multiple connection ports are located. The open accommodating space is for a single connection port that has been previously disposed on the motherboard. Thus, the single connection port such as a HDMI port, USB port, or display port on the motherboard may be housed in the accommodating space of the stacked connector when connected to the stacked connector and then becomes a unity with the stacked connector.
On the other hand, a conductive elastic strip is located in the accommodating space of the stacked connector to be in contact with the metal shell for the EMI shielding of the connection port on the motherboard. When the stacked connector is connected with the connection port on the motherboard, the conductive elastic strip will be pressed against a top surface of the connection port, which is away from the motherboard, to connect the connection port to the ground or to shield the connection port from the EMI by a contact relationship between the conductive elastic strip, the metal shell, and the motherboard.
However, some problems are involved in the above process. In general, the connection port of the circuit board is covered by the stacked connector such that pins of the stacked connector penetrate through the motherboard. Next, the pins of the stacked connector are welded to the motherboard by for example reflow soldering. Particularly, since the conductive elastic strip in the connection port on the motherboard in contact with the stacked connector is resilient in nature and therefore easy to be separate from or in loose connection with the connection port owing to any vibration or shake during the process, not all of the pins of the stacked connector can penetrate through the motherboard to a sufficient extent. As a result, part of the pins of the stacked connector will not be welded to the motherboard firmly and stably, thus forming some soldering defects like solder skip and solder short and after all affecting negatively the defective rate and quality and stability of digital signal transmission of the electrical connector.